Soil and root samples were collected from each 10-cm layer to 80 cm depth. All roots in each soil layer were carefully removed and rinsed with water to remove adhering Selleck PF-562271 soil. A 0.05 mm sieve was used to prevent the loss of fine roots during washing. Roots were placed into a zip-locking bag to soak up water and stored at − 20 °C. The roots in each layer were scanned with a scanner (Epson V700, Germany) to an image file. The WinRhizoPro5.0 software (Pro2004b, Canada) was used to evaluate root length, surface area, and diameter. The

root dry weight of each layer was evaluated after oven drying at 70 °C to constant weight. At the 12-leaf and early filling stages, soil samples from the soil layers were collected, and treated with 0.01 mol L− 1 CaCl2. A TRACCS2000 continuous flow analyzer was used to determine the ammonium and nitrate nitrogen contents of the soil. The Olsen method was used to test readily available phosphorus of the soil and the water content was also measured at the 12-leaf stage [29]. A soil hardness tester (Yamanaka type, Japan) was used to measure the soil compaction of the 0–80 cm soil layer at the 12-leaf stage. Microsoft Excel 2007 software

was used for data processing and drawing, and SAS 8.0 statistical software was used for variance analysis and multiple comparisons. Significant differences in biomass and grain yields were found among the three treatments (Table 1). Under the T1 and T2 treatments, grain yields were increased by 4.2–23.0% with an average of 12.8% and Dabrafenib in vivo Liothyronine Sodium dry biomass was increased by 9.2–24.5% with an average of 14.6%. Based on the yield components, subsoiling was responsible for an increase in grain weight, which, comparing T1 and T2 treatments with the control (CK), were increased by 12.7% and 15.2%, respectively. The number of ears was increased by − 0.2–0.7% with an average of 0.4% compared with the control (CK). The kernel number was increased by − 0.5–6.3% with an average of 2.7%. There was no significant difference between T1 and T2 treatments. Environment (year) had a significant

effect on biomass and grain yield and the interaction between year and treatment was also significant (Table 2). There were significant differences in precipitation and rainy period during 2009–2012 (Fig. 1), which influenced mainly the slight annual differences in yield components. Although rainfall was sufficient in early 2009, the grain weight was reduced by severe drought in later months of that year, resulting in no significant difference between treatments. Heavy precipitation events occurred mainly in late 2010, resulting in lower kernel number and significantly higher grain weight. Under the T1 and T2 treatments, grain weights were increased by 23.7 and 26.7%, respectively, compared to CK treatment. Grain yield and biomass showed a slight difference between treatments owing to increased rainfall in July and August, masking the effect of subsoil tillage.